Social Vulnerability Index Factors Related to Socioeconomic Status and Access to Care Among Adults Living with Sickle Cell Disease
Djaina-Shae Dervil, Danetta Hooks, Siobhan M Lawler, Nicole Farmer, Samuel M Degenhard, Rebecca M Metellus, Ashley Buscetta, Stephaine Wildridge, Li Yang, Allison Brichacek, Samuel Zamora, Vence BonhamAbstract
Background
Sickle Cell Disease (SCD) is a monogenic condition caused by an autosomal recessive pattern, producing abnormal hemoglobin (HBS), with complex social and pathophysiological pathways. According to the Center for Disease Control and Prevention (CDC), the Social Vulnerability Index (SVI) is a tool to identify communities that are at risk, where the higher the SVI score (range of 0 to 1.0) the more susceptible one is to adverse social and environmental factors, such as poverty, disability, crowded housing, and lack of transportation access. Prior research has demonstrated that living within an area with higher SVI is associated with increased all-cause mortality for adults living with SCD. Factors that contribute to this increased mortality, such as access to and type of healthcare, have not been reported to date. The objective of this analysis is to determine the relationship of factors related to socioeconomic status (SES) and measures related to health care access to SVI score among adults living with SCD.
Methods
The study is an observational mixed methods study started in 2022 at the National Institute of Health in Bethesda, MD with a sample size of 64 adults living with SCD in the United States. To ensure a diverse sample population for the study, participants were recruited in the United States with in-person or telehealth visits. In-person visits were conducted at the NIH Clinical Center. The telehealth visits were conducted for participants who resided more than 25 miles from the NIH Clinical Center. The data collected for this analysis included information such as sickle-cell genotype, race, sex, age, education status, household income, employment status and type, insurance status and type, medication use, last hospitalization in the last 12 months. SVI was determined by the participants’ address using the Centers for Disease Control and Prevention and Agency for Toxic Substances and Disease Registry Social Vulnerability Index (CDC/ATSDR SVI). The statistical tests used to test relationships were an independent sample t-test, one way ANOVA.
Results
Of the 64 participants, the mean age was 42.7 (±12.25, 21-71) years and 71.9% were female. Under the federal definition of race, 92.1% were African American, 3.2% were American Indian or Alaskan Native, 3.2% were white, and 1.6% were Asian. The median household income was 60,000-69,999. 34.9% of participants had a bachelor’s degree or a professional degree (Master, MD, PHD; 31.7%). 54% reported being employed at the time of the study and 41.3% were working full-time. Insurance type included private (45.3%), Medicare (23.4%), Medicaid (15.6%), military health care (1.5%), and other government insurance (7.8%). 31.7% of participants had been hospitalized in the last 12 months. The mean time since last hospitalization was 1.47 years (±1.33). 42.2% of participants did not take any medication, and hydroxyurea was the highest reported medication (39.1%). SCD genotype status was 67.2% HbSS, 25.0% HbSC, 6.3% HbSB+, and 1.6% HgbS alphathal. The average SVI score was 0.54 (±0.28) which shows that within the sample, on average there was a moderate level of social vulnerability. An independent samples t-test showed that insurance status was not significantly associated with SVI (p = 0.198). A one-way ANOVA showed no significant association between years since last hospitalization (ƞ²=0.02, 95%CI [0.00,0.06], p = 0.886), or medication use (ƞ²=0.06, 95%CI [0.00,0.15], p = 0.446) with SVI. However, insurance type and SVI did have a moderate association that trended towards statistical significance (ƞ²=0.14, 95%CI [0.00,0.27], p = 0.072). There was, however, a significant association with SVI and employment type (ƞ²=0.28, 95%CI [0.16,0.37], p = 0.013).
Conclusions
Within this sample, SVI was not statistically significantly associated with health care type, a measure of healthcare access but may be in a larger sample size. SVI was significantly associated with employment type and employment status, which may offer additional prospective of SVI as a tool to identify an individual’s susceptibility and adverse risk levels. The results warrant further investigation into factors related to socioeconomic status, and measures related to healthcare access, namely age, current health status of cohort, education, region, medication use and type, and genotype to adequately highlight a relationship to SVI. Factors, such as sample size, geographic phenotype, and selection bias of a population may have influenced the relationship between SVI and access to care. Future studies that include determination of SVI within larger cohort studies are needed to confirm these results.